GEN 2 Malfunction Indicator Lamp - Regulatory

[JefferyGT]

I had this exact same problem 3 times and have done a bunch of digging on it, here's what I've found:

P04DB shows up for me during extended normal highway driving. Once the DTC is triggered, Fordpass shows the 'regulatory' malfunction. On forscan it will show P04DB sometimes accompanyied by additional DTCs as it is for you.

Essentially the CAI is letting by too much air that the mass air flow sensor reads as a leak in the system and triggers the DTC.

You can safely reset the CEI on forscan and continue driving the truck. I would check your intake tubing to make sure that the sensor is fully seated and whatever gromet/o-ring has a nice seal on it.

This is such an issue that aFe Power offers a specific tube to insert down the intake towards the sensor to eliminate that problem. I've had that recommended to me my the great guys at JLT performance as they also regularly see P04DB on non-tuned trucks with a CAI.

Additionally, a tune will likely stop P04DB as the tune is going to factor in additional airflow.

Hello. Do you have any further information on this tube for the intake?
Cheers

 

[Braaaaptor]

Hello. Do you have any further information on this tube for the intake?
Cheers

Yup! Here's the link:

Magnum FORCE Cold Air Intake System Replacement Vent Tube Insert

.embed-container { position: relative; padding-bottom: 56.25%; height: 0; overflow: hidden; max-width: 100%; } .embed-container iframe, .embed-container object, .embed-container embed { position: absolute; top: 0; left: 0; width: 100%; height: 100%; } Prevents the P04DB Check Engine Light...

afepower.com